RYAZANOV, V. Nonequilibrium statistical operators for systems with finite lifetime. ФІЗИКА НИЗЬКИХ ТЕМПЕРАТУР, Харків, Україна, v. 33, n. 9, p. 1049–1051, 2007. DOI: 10.1063/1.2784144. Disponível em: http://80.92.230.95/index.php/fnt/article/view/f33-1049e. Acesso em: 11 лис. 2025.